There is a known technique for superimposing an image or the like on a predetermined position of a captured image and transmitting the superimposed image. A known example is an on-screen display function (hereinafter, referred to as an OSD function) for displaying information, such as an image, at a fixed position of a captured image.
There is another known technique for dynamically changing a position of a captured image at which an image is to be superimposed. For example, PTL 1 discloses an image-capturing apparatus that moves the position of a cursor on a display screen in a panning or tilting direction in which the body of the apparatus moves.
However, increasing diversity of an image superimposing process sometimes causes a mismatch between the maximum number of superimposable images, which depends on individual superimposing processes, and the maximum number of images that can be set by the image-capturing apparatus as a whole.
Furthermore, there is no interface that provides the maximum number of images that can be superimposed by individual image superimposing processes to an external apparatus.
This poses the problem of difficulty in providing the maximum number of actually superimposable images from an image-capturing apparatus to an external apparatus to which superimposition images are to be set, so that normal superimposition image setting cannot be performed from the external device.